Introduce nginx configuration for rate limiting

[suhlig]

Thanks for contributing to the cloud_controller_ng. To speed up the process of reviewing your pull request please provide us with:

• A short explanation of the proposed change:

  This change introduces rate limiting to API calls to the Cloud Controller by exposing the limit_req nginx configuration setting. The rate limiting proposed is applied per user, using nginx' $http_authorization variable.

• An explanation of the use cases your change solves

  It will prevent overloading the cloud controller with too many requests. It protects legit requests by applying the limit per-user.

• I have viewed signed and have submitted the Contributor License Agreement

• I have made this pull request to the master branch

• I have run all the unit tests using bundle exec rake

• I have run CF Acceptance Tests on bosh lite

Please note that the change was implemented by @petergtz and @jordanj.

@smoser-ibm & @suhlig from the Flintstone team

[cfdreddbot]

Hey suhlig!

Thanks for submitting this pull request! I'm here to inform the recipients of the pull request that you and the commit authors have already signed the CLA.

[cf-gitbot]

We have created an issue in Pivotal Tracker to manage this:

https://www.pivotaltracker.com/story/show/127533505

The labels on this github issue will be updated when the story is started.

[thausler786]

Hey @suhlig,

Thanks for the pull request. We tested it out and were able to get it to successfully rate limit, and it passes our test suites when unconfigured.

Merged!

@thausler786
CAPI team member